Our long-term objective is to gain a greater understanding of how the visual system processes information, in particular the extent to which, and how, we use color and luminance variations in the environment to detect and characterize the shape and movement of objects. The information present in the visual world consist of relatively independent variations across the field in the wavelength and in the intensity of light. With our acute color vision, we can potentially utilize each of these types of information to detect the presence of objects and to identify what they are. In psychophysical experiments, we are asking to what extent these two types of information are actually used by human observers for characterizing the shape of objects and in specifying the direction and speed of movement. In physiological-anatomical experiments, we are asking how cells respond to stimuli which vary in color vs luminance, and whether color and luminance information are dealt with in different anatomical locations within the visual cortex.